the world honors the legacy of nelson mandela. former secretaries of state colin powell and james baker share their memories with us. plus, rock star bono on his friend's wisdom and courage. >>> relentless cold batters much of the country. the ice storm threatens to disrupt the lives of millions. >>> and one of the last survivors of what could be the most important treasure hunt history. >>> but today, your world in 90 seconds. >> for me, he had hope, he represented freedom. so, today, i'm here to show i'm thankful for him! the world mourns the passing of an icon. >> nelson mandela died at his home surrounded by his family. >> went from the prison cell to the presidency with such unmatched grace. >> i think we try to prepare ourselves, but emotionally, it's not that easy. >> crowds gathering outside the home in johannesburg. ♪ >> he was a father figure to the nation. the one thing we all had in common. >> justice for all, let freedom ring. god bless. >> millions of americans are facing another big blast of winter weather. >>> th